1. Field of the Invention
This invention relates in general to a light weight analyzer capable of detecting and recognizing odor volatile chemicals. In particular, the light weight analyzer is capable of detecting clandestine burial sites of human remains and detecting and recognizing odors emitted from human remains, such as decomposed human remains.
2. Description of the Related Art
Locating clandestine graves, identification of victims (development of biological profiles from unidentified persons), and odor recognition (in locating and identifying individuals) are very difficult, costly and time consuming tasks which impact law enforcement, intelligence and military operations around the world.
Locating buried human remains, in particular, is one of the most difficult tasks currently facing archeologists, anthropologists, and law enforcement personnel. Investigations to locate clandestine graves are time consuming and costly. Typical burials are not located in less than 10 years and many of those are either accidental discoveries or are identified by the perpetrator. Many criminal burials occur in remote areas, are typically shallow and are typically wrapped in some type of material. Additionally, the slow diffusion of material from the soil and the length of internment make locating clandestine graves via vegetational changes very challenging.
There are three primary means of locating clandestine graves today: manual probing, ground penetrating radar (GPR), and canines. Many agencies usually employ a combination of all these methods when searching for clandestine graves, mass graves, or missing persons. Manual probing is very inexpensive and is used to locate disturbed soil regions, but cannot confirm the presence of a corpse and can only be used in small areas. Ground-penetrating radar (GPR) has been used for several years as a non-destructive method of locating subsurface anomalies. GPR is usually expensive and also locates areas of disturbed soil. Under ideal conditions, and if the grave is very fresh, GPR can sometimes indicate the presence of a corpse, but objects in the environment (e.g. roots, stumps, rocks, debris, man-made objects, etc.) can yield false-positive results and a significant amount of training is required to interpret the signals indicative of clandestine graves. No matter how the data is processed and visualized, GPR units can only penetrate to a limited depth. As the electromagnetic pulses dissipate with depth, they eventually fade to nothingness.
For centuries, canines have had a well-established and integral part in law enforcement. They have proven to be invaluable in such vital areas as explosive detection, narcotics detection, and tracking and searching for criminals, lost persons and missing persons. The ability of dogs to detect human scent is strongly documented throughout the literature.
Human scent is composed of skin flakes, perspiration, skin oils and gaseous components. Depending upon the task, police canines utilize different aspects of these components. When tracking the scent of a suspect, the canine follows the skin flakes and disturbances to ground vegetation. If the task is article recovery, skin oils of the suspect have contaminated the object being sought. Canines are capable of locating such objects (e.g. guns) up to 48 hours later. For example, police canine can detect a hidden suspect from airborne scents of fatty acids in the skin oils.
It is reported that a comparison of olfactory cell counts between humans and canines indicate that a dog's sense of smell is at least 44 times better. In addition, dogs are able to distinguish the odors of different people, and it is believed that the most probable advantage canines possess is scent discrimination or the ability to distinguish one scent from another. However, a dog's ability to locate gravesites when no physical evidence is present still remains a mystery.
Canines that detect human remains, commonly referred to as human remains detection (HRD) canines, have been minimally represented in the law enforcement canine population across the United States. Their ability to locate as little as 5-15 mg of human tissue, blood, or bone, either buried, on the surface, or elevated above the ground, exceeds the ability of current instrumentation. In addition, it has been reported that HRD canines have identified remains, graves over 100 years old, and minute amounts of human material (even when masked). Given their reported abilities, HRD canines are still not the final answer for grave detection today primarily because of a lack of standardization in their training procedures and a poor understanding of their scenting capabilities. Research has shown that the odor of decomposition changes over time, therefore, an HRD canine trained only on tissue will potentially have a more difficult time detecting bone material since the lack of tissue has caused the composition of the odor signature to change.
Unfortunately, empirical evidence documenting how the canine utilizes their amazing olfactory skills is far from complete and little scientific testing of law enforcement canines has been conducted. The current concern facing cadaver dog units is that training is inadequate since it is unknown to what odor signals the dogs respond to when alerting and the alerting may not completely be in response to odor. This jeopardizes search and seizure as well as probable cause rules currently established for search warrants and chain of custody. Furthermore, it is not feasible for many agencies to have an HRD program.
Forensic chemistry is one of the most important sub-disciplines of forensic science, providing detailed analytical information to investigators of crimes involving drugs, explosives, toxic chemicals and biological substances. Chemical analysis is primarily conducted in laboratories on samples collected in the field or at a crime scene using a “best guess” sampling strategy. Sample turn-around times in the laboratories can be long (many days) and important samples may be missed at the crime scene due to a lack of information during the collection process. Low-cost chemical sensing equipment that is easy to operate would significantly enhance the ability of crime scene investigators to locate and collect samples, avoid missing critical evidence, and reduce the number of times that a site must be revisited to collect additional samples.
U.S. Patent Application Publication No. 2008/0028827 describes a significant advance in methods and devices for detecting a burial site of human remains. In view of the advances in the art provided by the device of U.S. Patent Application Publication No. 2008/0028827, even further improvements to this technology would be beneficial.